I have no idea what the profile or demographic of Facebook users is, but check out this Causes page: http://apps.facebook.com/...
Out of the 924,683 people that signed in to change their status to a message about getting out to vote tomorrow, 67% of them chose Obama to 20% for McCain. That's a good, solid drubbing.
Hey, it's just as important a fact as the one that says when the Redskins lose, the incumbent loses too! :)